People with adequate WiFi but poor cell service can find their incoming calls going to voice mail if there phone has been sleeping for a while. This happens because after sleeping for an hour or more the Doze function puts apps to sleep. When a call comes in RW attempts to awaken the phone but it doesn’t wake up fast enough to reply to RW’s interrogation. RW sends the call to cell but if cell service is unavailable the call goes to voicemail.
There is a work-around for this problem:
- Go to the Play store and install the free Macrodroid app:
- Make this macro:
The macro turns the screen on every 50 minutes preventing the phone from entering the Doze mode. This will drain the battery a little faster depending on one’s display settings. The app can be turned on and off with a simple toggle.
It is quite likely this work-around will also fix a problem where WiFi disconnects in Doze which, in turn, causes the phone to use cellular data (if LTE service is available) while connected to WiFi. That problem can also be fixed by toggling WiFi off and back on again but the Macrodroid work-around makes that unnecessary.
Update: I solved this problem but the solution is unique to my phone (Samsung Galaxy S7) and my ASUS router. I updated the firmware on my routers, enabled WMM-APSD, and in the Device Maintenance section of my S7 I turned App Power Monitor ON and added The Republic Wireless and Anywhere apps to the list of unmonitored apps. It is no longer necessary for me to use Macrodroid. Since taking these steps I’ve continuously maintained a solid RW arc whether charging or not charging and all test calls ring through.
Update: Here is another somewhat obscure reason for disconnects: